Japan Patent No. 4657034 discloses a connector that has a Connector Position Assurance (CPA) function. This connector includes a first housing, a second housing to be engaged with the first housing, and further a sliding member. The sliding member is attached to the second housing in a slidable manner from a first position (stand-by position) that is an initial position to a predetermined second position (engagement locking position) upon completion of the engagement of the second housing with the first housing. This sliding member serves as a CPA member that enables a user to check the completion of the engagement of both the housings by a sliding action from the first position to the second position.